Hi....This is my submission for the "one hour design challenge".......Took me 58 minutes to finish the ideation sketches.........I use black hard and soft pencil for the hands, mechanism and other elements of the design of the prothesis, ball point pen por the final product, photoshop for some composition and digital tablet for shadows. Small sketches and continuos line help to save a lot of time when sketching............Hope you like it.......